Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS6940636 B2
Publication typeGrant
Application numberUS 09/957,117
Publication dateSep 6, 2005
Filing dateSep 20, 2001
Priority dateSep 20, 2001
Fee statusPaid
Also published asUS20030053233
Publication number09957117, 957117, US 6940636 B2, US 6940636B2, US-B2-6940636, US6940636 B2, US6940636B2
InventorsLawrence E. Felton
Original AssigneeAnalog Devices, Inc.
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Optical switching apparatus and method of assembling same
US 6940636 B2
Abstract
In an optical switching apparatus having a mirror structure bonded to a substrate, the gap between the mirror structure and the substrate is controlled by mechanical standoffs placed between the mirror structure and the substrate. The mirror structure is bonded to the substrate using solder. The mechanical standoffs are formed from a material having a higher melting point than that of the solder. The mirror structure is bonded to the substrate under pressure at a temperature between the melting point of the solder and the melting point of the mechanical standoffs.
Images(4)
Previous page
Next page
Claims(15)
1. A method for assembling an optical networking device, the optical networking device comprising a mirror structure bonded to a substrate, the method comprising:
forming a number of mechanical standoffs on at least one of the mirror structure and the substrate by depositing a first material to a thickness at least equal to a predetermined mechanical standoff thickness; and
forming a number of electrical contacts between the mirror structure and the substrate from a second solder material having a lower melting point than the first material; and
bonding the mirror structure to the substrate under pressure at a temperature between the melting point of the first material and the melting point of the second solder material so that the second solder material melts to form mechanical and electrical bonds.
2. The method of claim 1, wherein forming the number of electrical contacts comprises forming the number of electrical contacts on one of the substrate and the mirror structure.
3. The method of claim 2, wherein forming the number of electrical contacts on one of the substrate and the mirror structure comprises:
depositing a solderable surface; and
depositing the second solder material onto the solderable surface.
4. The method of claim 1, wherein forming the number of mechanical standoffs on one of the substrate and the mirror structure comprises:
depositing the first material to a thickness greater than a predetermined mechanical standoff thickness; and
removing some of the deposited first material to obtain the predetermined mechanical standoff thickness.
5. The method of claim 1, wherein the first material comprises one of:
a solder material having a higher melting point than the second solder material;
a metallic material having a higher melting point than the second solder material; and
a glass material having a higher melting point than the second solder material.
6. The method of claim 1, wherein the number of electrical contacts are formed to a thickness greater than that of the mechanical standoffs, and wherein the number of electrical contacts are compressed during said bonding.
7. An apparatus comprising:
a mirror structure;
a substrate;
a number of mechanical standoffs formed from a first material deposited to a thickness it least equal to a predetermined mechanical standoff thickness on at least one of the mirror structure and the substrate for physically separating the mirror structure from the substrate by a predetermined distance; and
a number of electrical contacts formed from a second solder material having a lower melting point than the first material, wherein the mirror structure is bonded to the substrate under pressure at a temperature between the melting point of the first material and the melting point of the second solder material so that the second solder material melts to form mechanical and electrical bonds.
8. The apparatus of claim 7, wherein the first material comprises one of:
a solder material having a higher melting point than the second solder material;
a metallic material having a higher melting point than the second solder material; and
a glass material having a higher melting point than the second solder material.
9. The apparatus of claim 7, wherein the electrical contacts are formed onto one of the mirror structure and the substrate.
10. An optical switching apparatus comprising a mirror structure bonded to a substrate through the process of:
forming a number of mechanical standoffs on at least one of the mirror structure and the substrate from a first material deposited to a thickness at least equal to a predetermined mechanical standoff thickness; and
forming a number of electrical contacts between the mirror structure and the substrate from a second solder material having a lower melting point than the first material; and
bonding the mirror structure to the substrate under pressure at a temperature between the melting point of the first solder material and the melting point of the second material so that the second solder material melts to form mechanical and electrical bonds.
11. The optical switching apparatus of claim 10, wherein the number of electrical contacts are formed on one of the substrate and the mirror structure.
12. The optical switching apparatus of claim 11, wherein the number of electrical contacts are formed on one of the substrate and the mirror structure through the process of:
depositing a solderable surface; and
depositing the second solder material onto the solderable surface.
13. The optical switching apparatus of claim 10, wherein the number of mechanical standoffs are formed on one of the substrate and the mirror structure through the process of:
depositing the first material to a thickness greater than a predetermined mechanical standoff thickness; and
removing some of the deposited first material to obtain the predetermined mechanical standoff thickness.
14. The optical switching apparatus of claim 10, wherein the first material comprises one of:
a solder material having a higher melting point than the second solder material;
a metallic material having a higher melting point than the second solder material; and
a glass material having a higher melting point than the second solder material.
15. The optical switching apparatus of claim 10, wherein the number of electrical contacts are formed to a thickness greater than that of the mechanical standoffs, and wherein the number of electrical contacts are compressed during said bonding.
Description
FIELD OF THE INVENTION

The present invention relates generally to optical networking, and more particularly to an optical networking apparatus and a method for assembling same.

BACKGROUND OF THE INVENTION

Micro Electro-Mechanical Systems (MEMS) for use in optical switching applications typically contain optical mirrors that are controllable electronically. The optical mirrors are typically micro-machined from a silicon wafer and coated with various materials to produce a reflective mirror surface. The mirror structure is typically bonded onto a substrate, and the resulting structure is typically packaged within a glass-covered package. The glass allows light to pass to and from the optical mirrors.

The substrate typically includes electrode pads that are used to control the position of the optical mirrors, and also includes various electrical contacts. When the mirror structure is bonded onto the substrate, the electrical contacts on the substrate need to make contact with electrical contacts on the mirror structure, and the optical mirrors must be positioned a precise distance above the electrode pads. This is because the voltage required to position a mirror depends on the distance of the mirror from the electrode pads, and variations in the distance between the mirrors and the electrode pads make it difficult to control the position of the mirrors.

SUMMARY OF THE INVENTION

In accordance with one aspect of the invention, the gap between the mirror structure and the substrate of an optical switching apparatus is controlled by mechanical standoffs placed between the mirror structure and the substrate. The mechanical standoffs are typically deposited onto the substrate and formed to a very precise thickness. The mirror structure is bonded to the substrate using solder, which typically also forms the electrical connections between the substrate and the mirror structure. For convenience, the solder used for bonding the mirror structure to the substrate and for making the electrical connections is referred to hereinafter as the bonding solder. The mechanical standoffs are made from a material that has a higher melting point (MP) than the bonding solder. The mirror structure is bonded to the substrate under pressure at a temperature between the bonding solder MP and the mechanical standoff MP. Thus, the bonding solder melts to form the appropriate mechanical and electrical bonds, but the mechanical standoffs do not melt and therefore maintain a precise gap between the mirror structure and the substrate.

In accordance with another aspect of the invention, a method for assembling an optical networking device having a mirror structure bonded to a substrate involves forming a number of mechanical standoffs between the mirror structure and the substrate from a first material, forming a number of electrical contacts between the mirror structure and the substrate from a second solder material having a lower melting point than the first material, and bonding the mirror structure to the substrate under pressure at a temperature between the melting point of the first material and the melting point of the second solder material. The electrical contacts may be formed on the substrate and/or the mirror structure, which typically involves depositing a solderable surface and depositing the first solder material onto the solderable surface. Likewise, the mechanical standoffs may be formed on the substrate and/or the mirror structure, which typically involves either depositing the second material to a predetermined mechanical standoff thickness or depositing the second material to a thickness greater than a predetermined mechanical standoff thickness and removing some of the deposited second material to obtain the predetermined mechanical standoff thickness. The second material is typically either a solder material having a higher melting point than the second solder material, a metallic material having a higher melting point than the second solder material, or a glass material having a higher melting point than the second solder material. The number of electrical contacts are typically formed to a thickness greater than that of the mechanical standoffs so that the number of electrical contacts are compressed during said bonding.

In accordance with yet another aspect of the invention, an apparatus includes a number of mechanical standoffs formed from a first material for physically separating the mirror structure from the substrate by a predetermined distance and a number of electrical contacts formed from a second solder material having a lower melting point than the first material for bonding a mirror structure to a substrate. The first material is typically either a solder material having a higher melting point than the second solder material, a metallic material having a higher melting point than the second solder material, or a glass material having a higher melting point than the second solder material. The apparatus may be either the substrate or the mirror structure.

In accordance with still another aspect of the invention, an optical switching apparatus includes a mirror structure bonded to a substrate through the process of forming a number of mechanical standoffs between the mirror structure and the substrate from a first material, forming a number of electrical contacts between the mirror structure and the substrate from a second solder material having a lower melting point than the first material, and bonding the mirror structure to the substrate under pressure at a temperature between the melting point of the first material and the melting point of the second solder material. The electrical contacts may be formed on the substrate and/or the mirror structure through the process of depositing a solderable surface and depositing the second solder material onto the solderable surface. Likewise, the mechanical standoffs may be formed on the substrate and/or the mirror structure through the process of depositing the first material to a predetermined mechanical standoff thickness or depositing the first material to a thickness greater than a predetermined mechanical standoff thickness and removing some of the deposited first material to obtain the predetermined mechanical standoff thickness. The first material is typically either a solder material having a higher melting point than the second solder material, a metallic material having a higher melting point than the second solder material, or a glass material having a higher melting point than the second solder material. The number of electrical contacts are typically formed to a thickness greater than that of the mechanical standoffs so that the number of electrical contacts are compressed during said bonding.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIG. 1 shows an exemplary optical mirror assembly including a mirror structure bonded to a substrate in accordance with a process of the present invention;

FIG. 2 shows an exemplary substrate assembly including electrical contacts formed from a first solder material and mechanical standoffs formed from a second solder material having a higher melting point than that of the first solder material in accordance with an embodiment of the present invention;

FIG. 3 shows a cross-sectional view of the substrate assembly along the plane of the electrical contacts in accordance with an embodiment of the present invention;

FIG. 4 shows a cross-sectional view of the substrate assembly along with plane of the mechanical standoffs in accordance with an embodiment of the present invention; and

FIG. 5 is a flow diagram describing a process for assembling an optical switching device in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

In an embodiment of the present invention, the gap between the mirror structure and the substrate is controlled by mechanical standoffs placed between the mirror structure and the substrate. The mechanical standoffs are typically deposited onto the substrate and formed to a very precise thickness. The mirror structure is bonded to the substrate using solder, which typically also forms the electrical connections between the substrate and the mirror structure. For convenience, the solder used for bonding the mirror structure to the substrate and for making the electrical connections is referred to hereinafter as the bonding solder. The mechanical standoffs are made from a material that has a higher melting point (MP) than the bonding solder. The mirror structure is bonded to the substrate under pressure at a temperature between the bonding solder MP and the mechanical standoff MP. Thus, the bonding solder melts to form the appropriate mechanical and electrical bonds, but the mechanical standoffs do not melt and therefore maintain a precise gap between the mirror structure and the substrate.

FIG. 1 shows an exemplary optical mirror assembly 100. Among other things, the optical mirror assembly 100 includes a mirror structure 110, a substrate 120, mechanical standoffs 130, electrical contacts 140, and electrode pads 150.

The mirror structure 110 is typically micro-machined from a single piece of silicon or a single silicon-on-insulator substrate to produce an optical mirror 112 that is movably suspended via tethers 111.

The electrical contacts 140 can be formed from any of a variety of solder materials, such as 63Sn-37Pb and 42Sn-588Bi. The electrical contacts 140 can be formed using any of a variety of techniques, including, but not limited to, screen printing techniques, stenciling techniques, and various placement techniques (e.g., placing individual solder balls). The electrical contacts 140 are typically deposited to a thickness greater than that of the mechanical standoffs 130, and are compressed during the bonding process when the mirror structure 110 is pressed onto the substrate 120. A solderable surface 160 is typically deposited onto both the mirror structure 110 and the substrate 120 so that the electrical contacts 140 adhere to both. Examples of solderable surfaces for both the mirror side and the substrate side include aluminum with a nickel gold solderability treatment, pure gold, and pure platinum. In addition, the substrate 120 could have a copper with nickel and gold solderability coating, thick film gold, or thick film nickel with a solderability coating. It should be noted that the present invention is in no way limited to any particular solder or solderable surface material or to any particular technique for forming the electrical contacts 140.

The mechanical standoffs 130 can be formed from any of a variety of materials having a higher MP than the bonding solder.

In one exemplary embodiment, the mechanical standoffs 130 are formed from solder having a higher MP than the bonding solder, such as 95Pb-5Sn, which melts at 305 C, and 95Pb-25In, which melts at 275 C. In such an embodiment, a solderable surface 160 is typically deposited onto the substrate 120, and the mechanical standoff solder is deposited on top of the solderable surface. The solder mechanical standoffs 130 can deposited using any of a variety of techniques, such as screen printing techniques, stenciling techniques, placement techniques, and placement of solder balls and solder preforms.

In another exemplary embodiment of the present invention, the mechanical standoffs 130 are formed from a metallic material (e.g., nickel) having a higher MP than the bonding solder. The metallic material can be deposited onto the substrate 120 with or without an adhesive layer, for example, using various electroplating techniques.

In yet another embodiment of the present invention, the mechanical standoffs 130 are formed from glass having a higher MP than the bonding solder. A glass frit material is typically used to produce the glass standoffs. The glass frit material is essentially a paste that includes a glass powder suspended in an organic binder. The glass frit material is typically deposited onto the substrate 120 using a screen printing technique. The organic compounds of the glass frit material are then burned off at a particular temperature, and the remaining glass powder is fired at a higher temperature in order to glaze the glass.

It should be noted that the present invention is in no way limited to any particular mechanical standoff material or to any particular technique for forming the mechanical standoffs 130, so long as the mechanical standoff material has a higher melting point than the bonding solder.

The mechanical standoffs 130 can be formed to the desired thickness using any of a variety of techniques. Typically, the mechanical standoffs 130 are deposited to a predetermined thickness that is within a predetermined tolerances. If the mechanical standoff material cannot be deposited to the desired thickness, then the mechanical standoffs can be built up layer by layer until the desired mechanical standoff thickness is reached, or the mechanical standoffs can be deposited to a thickness greater than the desired thickness and the excess material can be removed (e.g., by grinding or lapping) to obtain the desired thickness. It should be noted that the present invention is in no way limited to any particular technique for forming the mechanical standoffs to the desired thickness within the predetermined tolerances.

It should be noted that, wherever solder is used (i.e., for the electrical contacts 140 and possibly for the mechanical standoffs 130), the solder is typically deposited onto top of a solderable metallization layer. For depositing solder onto a silicon substrate, the solderable metallization layer may be formed from layers of aluminum, nickel, and gold.

FIG. 2 shows an exemplary substrate assembly 200 including the substrate 120 on which the electrical contacts 140, the mechanical standoffs 130, and a number of electrodes 210 are formed. In this example, both the electrical contacts 140 and the mechanical standoffs 130 are formed from a solder material, with the solder material for the mechanical standoffs 130 having a higher MP than the solder material for the electrical contacts 140. The electrode pads 150 (not shown) are formed on the electrodes 210.

FIG. 3 shows a cross-sectional view 300 of the substrate assembly 200 along the plane of the electrical contacts 140. For each electrical contact 140, a solderable metallization layer 320 is typically formed on top of the substrate 120, and the bonding solder 310 is deposited on top of the solderable metallization layer 320.

FIG. 4 shows a cross-sectional view 400 of the substrate assembly 200 along the plane of the mechanical standoffs 130. For each mechanical standoff 130, a solderable metallization layer 420 is typically formed on top of the substrate 120, and the mechanical standoff material 410 is deposited on top of the solderable metallization layer 420.

In a typical embodiment of the present invention, the mechanical standoffs are formed from a solder material having a higher MP than the bonding solder. The mechanical standoff solder is typically deposited before the bonding solder.

In order to form the mechanical standoffs, the mechanical standoff solder is deposited onto the substrate. The mechanical standoff solder is reflowed by heating it to a temperature above its melting point. During the reflow, the mechanical standoff solder melts and any flux and solvents evaporate or burn off. The mechanical standoff solder is typically formed to at least the desired thickness of the mechanical standoff, but may be deposited to a greater thickness and then lapped to the correct thickness.

Once the mechanical standoffs are formed, the electrical contacts are formed. In order to form the electrical contacts, solder balls are stencil printed or placed onto the substrate. The stencil for this operation is typically fabricated with cavities etched into the underside so as to accommodate the mechanical standoffs. The bonding solder is reflowed by heating it to a temperature above its melting point but below the melting point of the mechanical standoff solder. During the reflow, the bonding solder melts and any flux and solvents evaporate or burn off, but the mechanical standoff solder does not melt. The bonding solder is typically formed to a thickness exceeding that of the mechanical standoffs. This helps to ensure that the bond pads on the mirror structure make contact with the electrical contacts during the bonding operation.

Once the mechanical standoffs and electrical contacts are in place, the mirror structure is bonded to the substrate under pressure at a temperature between the bonding solder and the mechanical standoff solder. This allows the bonding solder to melt and form the mechanical and electrical bonds without destroying the mechanical standoffs.

FIG. 5 is a flow diagram describing a process 500 for assembling an optical switching device. Beginning at block 502, a number of mechanical standoffs are formed between the mirror structure and the substrate from a first material, in block 504. A number of electrical contacts are formed between the mirror structure and the substrate from a second solder material having a lower melting point than the first material, in block 506. The mirror structure is bonded to the substrate under pressure at a temperature between the melting point of the first material and the melting point of the second solder material, in block 508. The process 500 terminates in block 599.

It should be noted that there is no requirement that the mechanical standoffs be deposited prior to the bonding solder, and the present invention is in no way limited to depositing the mechanical standoffs prior to the bonding solder. In many cases, the mechanical standoffs can be deposited without having to be heated above the melting point of the bonding solder, and therefore the mechanical standoffs may be deposited after the bonding solder without damaging the bonding solder.

Although the above embodiments describe electronic contacts 140 and mechanical standoffs 130 formed onto the substrate 120, it should be noted that the electronic contacts 140 and/or the mechanical standoffs 130 could be formed onto the mirror structure 110.

It should be noted that, once the mirror structure 110 is bonded to the substrate, the assembly should be kept at temperatures below the bonding solder MP. Specifically, packaging processes should not use temperatures exceeding the bonding solder MP. Thus, for example, the assembly could be hermetically sealed into its packaging at a temperature below the bonding solder MP (i.e., step soldering), or the assembly could be sealed into its packaging using a seam sealing technique that uses localized heat for welding. It should be noted that the present invention is in no way limited to any particular packaging form or technique.

It should be noted that the described techniques for bonding a mirror structure to a substrate can be used generally for bonding a mirror array to an electrode array. The mirror array and/or the electrode array may be integrated with electronics.

The present invention may be embodied in other specific forms without departing from the true scope of the invention. The described embodiments are to be considered in all respects only as illustrative and not restrictive.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US4786357Nov 27, 1987Nov 22, 1988Xerox CorporationThermal ink jet printhead and fabrication method therefor
US4809901 *Aug 25, 1987Mar 7, 1989Raychem CorporationSoldering methods and devices
US5173392Apr 3, 1992Dec 22, 1992International Business Machines, Corp.Forming a pattern on a substrate
US5323051Dec 16, 1991Jun 21, 1994Motorola, Inc.Semiconductor wafer level package
US5535526 *May 25, 1995Jul 16, 1996International Business Machines CorporationApparatus for surface mounting flip chip carrier modules
US5594979Sep 13, 1984Jan 21, 1997Raytheon CompanyMethod for packaging a surface acoustic wave device
US5604160Jul 29, 1996Feb 18, 1997Motorola, Inc.Method for packaging semiconductor devices
US5761350Jan 22, 1997Jun 2, 1998Koh; SeungugMethod and apparatus for providing a seamless electrical/optical multi-layer micro-opto-electro-mechanical system assembly
US5798557Aug 29, 1996Aug 25, 1998Harris CorporationLid wafer bond packaging and micromachining
US5824177Jul 12, 1996Oct 20, 1998Nippondenso Co., Ltd.Method for manufacturing a semiconductor device
US5915168May 6, 1998Jun 22, 1999Harris CorporationLid wafer bond packaging and micromachining
US6297072Apr 16, 1999Oct 2, 2001Interuniversitair Micro-Elktronica Centrum (Imec Vzw)Method of fabrication of a microstructure having an internal cavity
US6327407 *Nov 6, 1998Dec 4, 2001Matsushita Electric Industrial Co., Ltd.Semiconductor light-receiving device, method of manufacturing the same, bidirectional optical semiconductor device, and optical transmission system
US6373620 *Jul 28, 1999Apr 16, 2002Corning Applied Technologies CorporationThin film electro-optic beam steering device
US6516671Jan 5, 2001Feb 11, 2003Rosemount Inc.Grain growth of electrical interconnection for microelectromechanical systems (MEMS)
US6543286 *Jun 19, 2001Apr 8, 2003Movaz Networks, Inc.High frequency pulse width modulation driver, particularly useful for electrostatically actuated MEMS array
US6555417Dec 5, 2001Apr 29, 2003Analog Devices, Inc.Method and device for protecting micro electromechanical system structures during dicing of a wafer
US6587626Jan 16, 2001Jul 1, 2003Corning IncorporatedLiquid overclad-encapsulated optical device
US6620642 *Jun 29, 2001Sep 16, 2003Xanoptix, Inc.Opto-electronic device integration
US6706546Jan 8, 2001Mar 16, 2004Fujitsu LimitedOptical reflective structures and method for making
US20020021055Jun 5, 2001Feb 21, 2002Lee Jin-HoMicro-actuator and manufacturing method thereof
US20020027294 *Mar 19, 2001Mar 7, 2002Neuhaus Herbert J.Electrical component assembly and method of fabrication
US20020045030Oct 16, 2001Apr 18, 2002Ozin Geoffrey AlanMethod of self-assembly and optical applications of crystalline colloidal patterns on substrates
US20020054422 *Jan 25, 2001May 9, 2002Carr Dustin W.Packaged MEMs device and method for making the same
US20020088988Jan 9, 2002Jul 11, 2002Kia SilverbrookLight emitting semiconductor package
US20020090180Jan 9, 2002Jul 11, 2002Kia SilverbrookWafer scale fiber optic termination
US20020109894Apr 16, 2002Aug 15, 2002Mems Optical, Inc.Vertical comb drive actuated deformable mirror device and method
US20030053233Sep 20, 2001Mar 20, 2003Felton Lawrence E.Optical switching apparatus and method for assembling same
US20030092229Jan 8, 2002May 15, 2003Kia SilverbrookUse of protective caps as masks at a wafer scale
US20030113067Nov 25, 2002Jun 19, 2003Seungug KohMultifunctional intelligent optical modules based on planar lightwave circuits
US20030119278Dec 20, 2001Jun 26, 2003Mckinnell James C.Substrates bonded with oxide affinity agent and bonding method
JP2001144117A Title not available
JP2001269900A Title not available
Non-Patent Citations
Reference
1Ko et al., Bonding Techniques for Microsensors, Micromachining and Micropackaging of Transducers, 1985, pp. 198-208.
2Lee et al., Fabrication of Silicon Optical Scanner for Laser Display; 2000, pp. 13-14.
3Petersen et al., Silicon Fusion Bonding for Pressure Sensors, Rec. of the IEEE Solid-State Sensor and Actuator Workshop, 1988, pp. 209-212.
4Roylance et al., A Batch-Fabricated Silicon Accelerometer, IEEE Trans. Electron Devices, Dec. 1979, vol. ED-26, No. 12, pp. 352-358.
5Rudolf et al., Silicon Microaccelerometer, Transducers' 87, Rec. of the 4<SUP>th </SUP>Int. Conf. on Solid-State Sensors and Actuators, 1987, pp. 376-379.
6Smith et al., Micromachined Packaging for Chemical Microsensors, IEEE Trans, Electron Devices, Jun. 1988, vol. 35, No. 6, pp. 192-197.
7Yoshio Awatani et al., Damage Free Dicing Method for MEMS Devices, International Conference on Opical MEMs Conference Digest, pp. 137-138, Aug. 20-23, 2002.
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US7608534Jan 26, 2005Oct 27, 2009Analog Devices, Inc.Interconnection of through-wafer vias using bridge structures
US8194305Sep 5, 2008Jun 5, 2012Silicon Quest Kabushiki-KaishaPackage for micromirror device
US8215151Jun 24, 2009Jul 10, 2012Analog Devices, Inc.MEMS stiction testing apparatus and method
US8619352Sep 5, 2008Dec 31, 2013Silicon Quest Kabushiki-KaishaProjection display system using laser light source
Classifications
U.S. Classification359/298, 359/291, 359/290
International ClassificationB81C3/00, G02B6/12, G02B6/35
Cooperative ClassificationG02B6/358, B81C3/001, G02B6/3512, G02B2006/12104, B81B2201/042, G02B6/3582
European ClassificationB81C3/00B, G02B6/35P8
Legal Events
DateCodeEventDescription
Feb 6, 2013FPAYFee payment
Year of fee payment: 8
Mar 6, 2009FPAYFee payment
Year of fee payment: 4
Nov 8, 2005CCCertificate of correction
Sep 20, 2001ASAssignment
Owner name: ANALOG DEVICES, INC., MASSACHUSETTS
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:FELTON, LAWRENCE E.;REEL/FRAME:012195/0982
Effective date: 20010821